Novartis and Merck Drugs Don’t Stop SARS-Related Virus in Study

March 13 (Bloomberg) -- Scientists have pinpointed a
protein that a new SARS-related virus uses to infect healthy
cells, in a study that may lead to treatments against it.

The new coronavirus that has killed at least nine people in
the past year latches to a protein called DPP4 on the surface of
cells, researchers from Erasmus Medical Center and Utrecht
University in the Netherlands wrote in the journal Nature today.
It’s the same protein that diabetes drugs such as Merck & Co.’s
Januvia and Novartis AG’s Galvus are designed to block, though
they were ineffective against the new virus, the study found.

Commercially available antibodies did prevent the virus
from infecting cells in lab dish experiments, though they
probably won’t be useful as treatments because they would kill
cells bearing DPP4, potentially causing damage to the lungs and
kidneys, said Bart Haagmans, an Erasmus virologist who led the
research. He and colleagues are now testing an experimental
vaccine in ferrets and monkeys that’s designed to block
infection without causing damage, though it’s years away from
being available for human use.

“It’s important that we think of strategies for these
emerging coronaviruses to develop vaccines in a fast and safe
way,” Haagmans said in a telephone interview from Rotterdam
today. “It’s a difficulty to get these vaccines quickly
developed.”

Januvia and Galvus may not have worked because the
coronavirus attaches to a different site on DPP4 to the area
that those drugs block, Haagmans said. He and colleagues are
working on a follow-up study to hone in on the exact site where
the virus docks.

Circulating Widely

A study reported last month showed the virus is susceptible
to a class of drugs called interferons that are approved to
treat hepatitis C infection, suggesting they could be used as
treatments.

The new virus, which is related to the one that killed 774
people in an outbreak of severe acute respiratory syndrome, or
SARS, in 2002 and 2003, is known to have infected 15 people in
the past year, and killed nine, according to a March 12
statement from the World Health Organization. Eight of the cases
and six of the deaths were reported in Saudi Arabia.

The virus is probably circulating more widely, but most
cases are showing few or no symptoms, Haagmans said. The virus
is genetically similar to a coronavirus found in bats,
suggesting it may have jumped from the winged mammals to humans
via an intermediate animal such as sheep or goats, Haagmans
said.

The two viruses are related “only like brothers who behave
very differently,” Gregory Hartl, a spokesman for the Geneva-based WHO, said in an e-mail today. The new virus shouldn’t be
described as SARS-like because the two pathogens are genetically
distinct, he said.

The new coronavirus can infect the lining of a person’s
airways faster than the SARS bug, according to a study published
last month, though researchers still don’t know how easy it is
to transmit from person to person.